Crohn's Colonosopy and Faecal Calprotectin

A member of my family was diagnosed with Crohn’s disease over 30 years ago. He had been sick for about five years before they finally made the diagnosis. He had lost a large amount of weight, had constant diarrhoea and was so tired he was unable to go to school. Today he is well and functions quite normally, but the whole family were traumatised by how long it took to make the diagnosis, and how sick he was.

At that time it was almost impossible to diagnose small bowel Crohn’s disease. They did a barium enema but this only really looked at the large bowel (colon). He did not have colonic disease. About one-third of people with Crohn’s have disease limited to the terminal ileum (end of small bowel). He was one of those.

Over the last few years it has become easier and easier to diagnose this nasty condition. Colonoscopy is much more widely available and allows direct imaging of the lining of the bowel where the inflammation takes place. In a reasonable proportion of patients it is also possible to enter from the caecum into the ileum to allow direct visualisation of the end of the small bowel. In people for whom this is not possible, an MRI of the small bowel now gives excellent images in a non-invasive way.

For some people abdominal and pelvic ultrasound done by an expert can also give a reasonably clear diagnosis although it is by no means fool proof. It is however completely non-invasive and does not even have the associated noise or claustrophobic feeling that comes with an MRI scan.

Combining abdominal and pelvic ultrasound with the latest test, a stool sample called a faecal calprotectin test, is perhaps the least invasive way forward ever developed. Calprotectin is a small protein that lives in the cells of the lining of the bowel wall. If there is inflammation, this protein is shed into the stool and it can be detected on a simple stool sample. An elevated faecal calprotectin on a small stool sample is a very good indicator there may be something wrong in the bowel. It is an excellent way of differentiating between situations where there is no inflammation such as in irritable bowel syndrome, and inflammatory bowel disease such as Crohn’s or ulcerative colitis where there is.

How things have changed. It took my family member five years to get his diagnosis. It was invasive, difficult and really quite unpleasant. These days we do not always even need to do a colonoscopy. A simple stool sample together with an ultrasound scan may be enough to make it clear what is wrong with the patient and to allow them to receive appropriate treatment